Erdogan says Turkey’s parliament will ratify Sweden’s entry into NATO if the U.S. sells Turkey fighter jets.

President Recep Tayyip Erdogan of Turkey said in comments reported on Tuesday that Turkey would approve Sweden’s bid to join the NATO military alliance if the United States went ahead with a sale of F-16 fighter jets and related technology to Turkey.

“If they keep their own promises, our parliament will keep the promise given,” Mr. Erdogan told reporters while returning to Turkey from a trip to Azerbaijan.

Sweden and Finland both applied to join NATO after Russia’s full-scale invasion of Ukraine last year, a process that requires the approval of all of the alliance’s members.

After months of delay, Mr. Erdogan agreed to allow Finland to join, which it did in April. But he has continued to hold out on Sweden, saying that the country harbors Turkish dissidents that his government considers terrorists.

After months of frustration, other NATO members thought a breakthrough had been achieved at the alliance’s summit in July in Vilnius, Lithuania, when it was announced that Turkey had agreed to approve Sweden’s bid. But Mr. Erdogan continued to say that Sweden needed to do more before the Turkish parliament would vote on the issue after its summer recess.

The parliament resumes in October, but it remains unclear when and if the Sweden vote will be scheduled.

In his comments on Tuesday, Mr. Erdogan explicitly linked the sale by the United States of F-16s to Turkey to its support for Sweden’s NATO bid, even though United States officials have repeatedly portrayed the two issues as separate. Mr. Erdogan said that if the United States goes through with the sale, it will fall to the Turkish parliament to approve Sweden’s bid.

Mr. Erdogan’s Justice and Development Party and its political allies hold a parliamentary majority, and most analysts say that if Mr. Erdogan decides to let Sweden in, the vote would be a mere formality.

The only other NATO nation that has yet to approve Sweden’s accession is Hungary, but Hungarian officials have said they would follow Turkey’s lead.